Opening the floor to PLCs and IPCs : CODESYS in UNICOS.
E. Blanco Vinuela, M. Koutli, T. Petrou, J. Rochez (CERN, Engineering Department, Geneva, Switzerland)
The CERN UNICOS (UNified Industrial COntrol System) framework is widely used in many process control domains (e.g. Cryogenics, Cooling, Gas Systems,
Ventilation, Vacuum…) to produce highly structured standardized control applications for the two CERN approved industrial PLC product families, Siemens and
Schneider. The CODESYS software suite, developed by the 3S (Smart Software Solution), provides an independent IEC 61131-3 programming environment for
industrial controllers. The complete CODESYS based development includes:
(1) a dedicated Java™ module plugged in an automatic code generation tool, the UAB (UNICOS Application Builder),
(2) the associated UNICOS baseline library for industrial PLCs and IPCs (Industrial PC) CODESYS v3 compliant,
(3) the Jython-based templates to deploy device instances and control logic.
The availability of this development opens the UNICOS framework to a wider community of industrial PLC manufacturers (e.g. Beckhoff, ABB, WAGO…) and, as the
CODESYS control Runtime works in standard Operating Systems (Linux, W7…), UNICOS could be deployed to any IPC.
The plug-ins are developed in Java™, while the Templates use a
scripting language: Jython. The format of the specification file is based
on xls/xml.
The format of the first four output files is PLCopen XML. These files are
afterwards imported in the CODESYS integrated software. The latter file
format is text-based and will be imported in the WinCC OA SCADA
SCADA : Screenshot of a WinCC OA synoptic
UAB architecture
Only represented the plug-ins related to
CPC (Continuous Control Process)
Outputs of the UAB CODESYS and Inputs
to the PLC and SCADA
Inputs to the UAB CODESYS
• The controller instances: all the UNICOSCPC objects described in the specification
(Programmable Organization Unit). In each
POU all the instances of this object are
• The controller communication: it contains
all the necessary parameters (e.g. IP
address…) required from the PLC/IPC to
establish the communication with the
• The process control logic: it contains the
specific logic required by the specifications
of the plant control.
• The topology: this file defines the cycle
scan and the execution order of all the
application POUs.
• The supervision database: a file
containing all CPC objects instances of the
application. It has also the communication
parameters for the IPC access and also the
mapping of all signal addresses to be
exchanged with the IPC.
• The specification file based on
the functional analysis of the
plant and containing all the
instances of the CPC objects.
• The Logic User Templates that
define the specific process
control logic. A default template is
provided to the user as a base, but
the process control engineer can
develop his own.
• The configuration parameters,
which should be filled in the wizard
communication parameters and
the mapping of the PLC memory
according to the needs of the
The hardware
Schneider SoMachine PLC
Why IPCs?
 It follows the IEC 61131-3 standard and supports the PLCOpen XML standard
exchange file format.
 It is executed as an independent runtime system into Windows or Linux operating
systems opening the floor to any IPC.
 Select the most suited platform for the real needs regardless of supplier.
 Avoid supplier specific language-extensions that prevent the inter-changeability.
 Reduce cost and time for migrating from devices manufactured by different vendors and
porting a program from one vendor’s programming software to another
 Nowadays many manufacturers offer a large
choice of hardware IPCs CODESYS
 Large archiving capabilities: In opposition to a
standard PLC, the internal memory of an IPC is
far less constrained.
 Advanced calculations: IPCs running
CODESYS can integrate complex algorithms
developed in high level programming languages
(e.g. C++).
 Performance: Hardware cycle time
considerable faster than PLCs
Beckhoff TwinCat IPC/PAC
 Around 300 manufacturers have integrated this product as the development
environment for their hardware.
 The integrated compiler transforms the CODESYS control code into native machine
code to be downloaded to the hardware. The most popular CPU families are
Local operation:
A subset of the UNICOS CPC SCADA functionality
Is implemented into Siemens and Schneider touch panels.
TwinCat Embedded PLC